Lab Abstract 1
Zoe Goodman
Lab Abstract 1
The purpose of this experiment is to learn how to test for common macromolecules and identify macromolecules in substances. The four tests that were used were: Sudan IV test, Iodine test, Biuret test, and Benedict’s test. The Sudan IV test identifies lipids. If the test is positive it will have a deep pink layer. Out of the four tested substances, only vegetable oil tested positive. The Iodine test determines if starch is present. In this test, potassium iodine reacts with starch molecules turning a blue or purple color. The starch substance was the only one tested to be positive for any of the substances. Benedict’s test is used to identify sugars. For this test, you add Benedict’s solution to a heated substance. If sugars are present, the substance will produce an orange or red color. The substances that tested positive were glucose, fructose, lactose, and Sprite. They tested positive because all of them had enough sugar to be detected. The Biuret test is used to detect proteins. A substance that contains two or more adjacent peptide bonds will form a purple complex. The higher number of bonds means a more intense color. Both Sprite and Half & Half tested positive. Although it seems these items wouldn’t contain proteins, they have just enough to be able to be detected. It was proved that various food contain a variety of macromolecules. Even though these tests worked, they’re not objective for trace substances. In the future, more sensitive testing agents should be used.
Keywords: Macromolecules, Lipids, Biuret test, Carbonyl groups, Glucose
Lab Abstract 1
The purpose of this experiment is to learn how to test for common macromolecules and identify macromolecules in substances. The four tests that were used were: Sudan IV test, Iodine test, Biuret test, and Benedict’s test. The Sudan IV test identifies lipids. If the test is positive it will have a deep pink layer. Out of the four tested substances, only vegetable oil tested positive. The Iodine test determines if starch is present. In this test, potassium iodine reacts with starch molecules turning a blue or purple color. The starch substance was the only one tested to be positive for any of the substances. Benedict’s test is used to identify sugars. For this test, you add Benedict’s solution to a heated substance. If sugars are present, the substance will produce an orange or red color. The substances that tested positive were glucose, fructose, lactose, and Sprite. They tested positive because all of them had enough sugar to be detected. The Biuret test is used to detect proteins. A substance that contains two or more adjacent peptide bonds will form a purple complex. The higher number of bonds means a more intense color. Both Sprite and Half & Half tested positive. Although it seems these items wouldn’t contain proteins, they have just enough to be able to be detected. It was proved that various food contain a variety of macromolecules. Even though these tests worked, they’re not objective for trace substances. In the future, more sensitive testing agents should be used.
Keywords: Macromolecules, Lipids, Biuret test, Carbonyl groups, Glucose